(1) Field of the Invention
This invention relates to electric motors and, more particularly, to electric motor components molded of conductive loaded resin-based materials comprising micron conductive powders, micron conductive fibers, or a combination thereof, substantially homogenized within a base resin when molded. This manufacturing process yields a conductive part or material usable within the EMF or electronic spectrum(s).
(2) Description of the Prior Art
Electric motors are used in a wide variety of products. Typical electric motors, such as those used in household applications, are a combination of metal and plastic components. Typically, the armatures and windings of the rotor, the commutator, and the can or case are formed of metal components. Other components, such as the end bell or the axle may comprise plastic, or resin-based, materials. The field magnets typically comprise ferrite materials such as certain metal oxides. The metal and magnetic components generate significant manufacturing cost and complexity and add substantial weight to the motor. An import object of the present invention is to replace several metal and/or magnetic components of prior art electric motor devices with components formed of a unique conductive loaded resin-based material of the present invention.
Several prior art inventions relate to electric motor components. U.S. patent application Publication US 2002/0148100 A1 to Du teaches an electric motor where a thermally conductive plastic material is injection molded over the armature of the motor to substantially encase the magnet wires. The thermally conductive plastic improves the thermal dissipation of the motor assembly to allow larger gauge magnet wires to be used and, additionally, allows a cooling fan to be molded simultaneously from the plastic material. U.S. Pat. No. 4,572,979 to Haar et al teaches a windshield wiper motor and gear mechanism having a one-piece plastic housing. U.S. Pat. No. 4,189,702 to Maloy teaches a rotating disk sonar device. Annular slip rings are electrically contacted by brushes. The slip rings may comprise a conductive plastic. U.S. Pat. No. 4,303,844 to Suzuki teaches a small DC motor having a magnetic plate disposed on an upper surface of the rotor. The magnetic plate comprises a conductive plastic.